A newbie Roku developer here. I know that if a video is played using the roVideoScreen object, pressing * will show the caption Settings UI. However, if I use roVideoPlayer to play the video, how do I trigger this same Caption Settings UI? Is there a programmatic way to launch the caption settings UI?
No, as far as I understand, if you are using roVideoPlayer component, none of the standard Roku UI components can be leveraged. You must draw the UI using roImageCanvas or Draw2D. I prefer the latter, as roImageCanvas is painfully slow on 2nd gen devices, and with 2D API you can do cool some custom animations and tweening (I mean its possible, but oops! you need to write a custom tweening engine for that)